Comprehensive diagnostic procedure to identify and isolate drivability issues on the 2024 Rivian EDV 500 dual motor electric delivery van, including electrical system verification, drivetrain component testing, and software diagnostics.

Warnings

Tools required

Parts

• 12V auxiliary battery (if defective) × 1 — Use OEM specification

Preparation

1. Verify customer complaint in detail: note specific conditions when drivability issue occurs (acceleration, deceleration, turning, cold/hot, load conditions)
2. Position vehicle on level surface in well-ventilated area with adequate clearance
3. Apply parking brake firmly and place wheel chocks at all four wheels
4. Verify 12V auxiliary battery voltage is above 12.4V; charge or replace if low as this affects all vehicle systems
5. Ensure technician is wearing appropriate high-voltage PPE including insulated gloves and safety glasses
6. Review any active or pending diagnostic trouble codes before beginning physical inspection
7. Photograph or document vehicle condition including odometer reading and dash warning lights
8. Verify sufficient charge in high voltage battery (minimum 20%) for drive testing if required

Procedure

1. 1

   Initial System Scan and Code Retrieval
   Connect Rivian diagnostic tool to OBD-II port located under driver side dash. Power on vehicle to accessory mode without enabling drive mode. Perform complete vehicle scan including powertrain, chassis, body, and battery management modules. Record all active and stored DTCs with freeze frame data. Pay particular attention to motor controller codes (P0Axx, P0Bxx series), battery management codes (P1xxx series), and inverter fault codes. Check for communication errors between modules which can cause intermittent drivability issues.
2. 2

   12V Auxiliary System Verification
   Test 12V auxiliary battery under load using battery tester. Verify voltage remains above 11.5V during 15-second load test. Check all 12V system connections including main battery terminals, ground points at frame rails, and body control module connections. Low or fluctuating 12V power causes erratic behavior in all vehicle systems including motor controllers. Inspect auxiliary battery junction box for corrosion or loose connections. Measure voltage drop across main power cables (should be less than 0.2V under load).
3. 3

   High Voltage Safety Verification and Isolation Status Check
   With vehicle powered off, verify high voltage disconnect status through diagnostic tool. Check that contactors are opening and closing properly. Listen for audible click when powering vehicle to ready mode indicating HV contactor engagement. Verify isolation resistance readings are within specification (typically above 500 ohms per volt). Low isolation resistance indicates potential HV leakage path that will cause drivability issues and safety concerns. Do not proceed with HV component testing if isolation fault is present.
   ⚠️If isolation fault is detected, do not touch any HV components. Vehicle requires immediate HV system inspection by certified EV technician.
4. 4

   Motor Controller and Inverter Inspection
   With HV system de-energized following manufacturer lockout procedures, perform visual inspection of front and rear motor inverter assemblies. Check for coolant leaks around inverter housings which can cause internal short circuits. Inspect HV cable connections at inverters for proper seating, corrosion, or arc damage. Verify inverter cooling system is functioning by checking coolant level in EV motor/battery coolant reservoir. Examine inverter mounting bolts for looseness which can cause vibration-related faults. Use thermal camera if available to identify hot spots indicating failing components after test drive.
5. 5

   Motor Resistance and Insulation Testing
   Using insulated multimeter with HV system locked out, measure phase-to-phase resistance on each motor (front and rear). All three phase pairs should read within 0.1 ohm of each other (typically 0.05-0.2 ohms total). Significant variance indicates internal motor winding damage. Measure insulation resistance from each phase to motor housing ground; should exceed 10 megohms. Low readings indicate winding insulation breakdown causing power loss and potential motor faults. Document all readings for comparison between front and rear motors.
6. 6

   Drivetrain Mechanical Inspection
   Raise vehicle safely on lift and secure with jack stands. Inspect front and rear drive units for oil leaks indicating seal failure. Check differential fluid levels in both front (1.5 qt capacity) and rear (2.0 qt capacity) units using fill plugs. Low fluid causes noise and potential damage. Rotate each wheel by hand feeling for roughness, grinding, or excessive resistance in drive unit bearings. Check CV axles and joints for boots tears, grease leakage, or play. Inspect transfer case fluid level (2.5 qt capacity). Examine all driveline mounts and bushings for damage or excessive wear.
7. 7

   Torque Vectoring and Traction Control System Test
   Using diagnostic tool, access torque distribution data and active traction control parameters. Perform stationary test activating each wheel independently through service mode if available. Verify each motor can respond to torque commands without fault codes. Check wheel speed sensor operation at all four corners; erratic or missing signals cause traction control intervention that feels like power loss. Clear any ABS/traction control codes and monitor for immediate return which indicates active failure. Review torque delivery logs to identify if one motor is not contributing properly during complaint conditions.
8. 8

   Battery Pack and Thermal Management Assessment
   Review battery state of health, cell voltage variance, and temperature distribution through diagnostic software. Individual cell voltage should be within 50mV of pack average. Cells outside this range cause pack imbalance reducing available power. Check battery thermal management system operation including coolant pump function, radiator fan operation, and temperature sensor readings. Verify EV battery/motor coolant level in reservoir (10 qt system capacity). Overheating or cold batteries significantly limit power output. Check for battery pack fault codes including cell voltage, temperature, or current sensor faults.
9. 9

   Accelerator Pedal and Sensor Verification
   Access accelerator pedal position sensor data through diagnostic tool. Verify smooth linear progression from 0-100% as pedal is depressed slowly. Check for signal dropout, spikes, or dead zones. Inspect pedal assembly mounting for looseness. Verify brake pedal position sensor correlation; improper signal can cause power limiting. Test regenerative braking response by monitoring motor torque values during deceleration. Inconsistent regen behavior indicates sensor or controller issues. Verify proper operation of drive mode selection (normal, sport, conserve) and that mode changes affect power delivery as expected.
10. 10

    Software Version and Update Status Check
    Verify all control modules are running current software versions through diagnostic tool. Check for available updates particularly for motor controllers, battery management system, and vehicle control unit. Review technical service bulletins for known drivability issues matching symptoms. Outdated software frequently causes power delivery issues, torque limiting, or communication faults. Document current software versions for all powertrain-related modules. Note if vehicle is reporting pending updates or failed update attempts which can cause degraded performance mode.
11. 11

    Road Test with Data Logging
    With diagnostic tool connected and data logging active, perform controlled road test duplicating complaint conditions. Monitor real-time parameters including motor torque output (front and rear), battery current, state of charge, motor and inverter temperatures, accelerator pedal position, and vehicle speed. Attempt to reproduce issue noting exact conditions. Record whether issue occurs during acceleration, cruising, or deceleration. Check if fault is speed-related, load-related, or temperature-related. Verify both motors are producing requested torque equally. Look for power limiting events or fault codes that appear during driving.
    ⚠Ensure safe traffic conditions for testing. Have second technician monitor diagnostic data while driver focuses on vehicle operation and traffic.
12. 12

    Post-Test Data Analysis and Fault Isolation
    Review captured data logs comparing to known-good values and specifications. Identify any anomalies in motor performance, battery delivery, or control system response. Cross-reference any fault codes that appeared during testing with freeze frame data showing exact conditions. Determine if issue is related to front motor, rear motor, battery pack, thermal management, or control system. Check for patterns such as faults only occurring when battery is hot, cold, at low state of charge, or under high power demand. Correlate customer complaint with captured data to confirm root cause.
13. 13

    Communication Network and Module Testing
    Test CAN bus communication integrity between powertrain modules using diagnostic tool. Verify message transmission rates and check for bus-off events or communication errors. Inspect wiring harness routing for damage, particularly orange HV cables and powertrain communication harnesses. Check for water intrusion in module connectors or junction boxes. Loose or corroded connections in communication circuits cause intermittent faults that are difficult to reproduce. Perform wiggle test on suspect connectors while monitoring for communication faults. Verify proper ground circuit integrity at motor controllers and battery management modules.
14. 14

    Final Diagnosis Documentation and Repair Recommendation
    Compile all test results, fault codes, data logs, and inspection findings into comprehensive diagnostic report. Clearly identify root cause of drivability complaint with supporting evidence. Provide specific repair recommendations with parts needed if applicable. Document any conditions that could not be reproduced and recommendations for extended monitoring. Note any additional concerns discovered during diagnosis such as pending failures or maintenance needs. If fault could not be isolated, document all systems verified as functioning correctly and recommendations for continued diagnosis or monitoring. Provide customer explanation of findings in clear non-technical language.

Reassembly

1. Reinstall any components removed during inspection ensuring all HV connections are properly torqued and secured
2. Verify all fluid levels are correct after any inspection or testing
3. Ensure all body panels, covers, and shields are reinstalled properly
4. Remove wheel chocks and lower vehicle from lift safely
5. Clear any diagnostic test codes that were set during testing procedures
6. Restore vehicle to customer-ready condition

Verification

• Perform final system scan to verify no new fault codes are present
• Confirm all warning lights extinguish properly when vehicle is powered to ready mode
• Verify 12V auxiliary battery voltage is stable above 12.6V with vehicle off
• Test drive vehicle confirming drivability issue is either resolved or consistently reproduced for further repair
• Verify proper torque delivery from both front and rear motors through diagnostic tool
• Confirm battery state of charge and state of health are within normal parameters
• Document final odometer reading and any remaining customer concerns
• Provide customer with detailed explanation of diagnosis results and recommended repairs if applicable

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